Synthesis And Properties Of Long Carbon Chain Gemini Phosphate Ester Surfactant

Gemini phosphate surfactants were reputed as a new generation of surfactants. As a special structure with two hydrophilic head groups and two hydrophobic groups, they have some especial physical and chemical characteristics such as low cmc,high surface activities and water solubility. In this paper, a new anion Gemini surfactants—C₁₈ alkyl Gemini phosphate surfactants were synthesized, their structures were determined and the properties were studied.The C₁₈ alkyl Gemini phosphate surfactants was synthesized by three steps:The first step, use the method of Phase Transfer Catalytic, in the condition of anhydrous, synthesizing C_16～18 alkyl glyceryl ether. Purification of reaction mixture was performed by reduced pressure and the productivity was 71.4%.By analyzing the IR aim product, the structure was confirmed. In addition, ameliorated the conventional way of measuring to the epoxy value.The second step, the C₁₈ alkyl digomeric glycol-intermediate product of gemini phosphate surfactant was prepared by opening ring reaction of C_16～18 alkyl glycide ether with glycol in the presence of potassium as catalyst. Purification of reaction mixture was performed by reduced pressure and the productivity was 58.7%.The third step, the C₁₈ alkyl Gemini phosphate was synthesized the C₁₈ alkyl digomeric glycol and phosphatizing agent P₂O₅ by phosphatation, the productivity was 77.6%. Then, neutral by KOH and get the C₁₈ alkyl Gemini phosphate surfactants.In addition, some properties of C₁₈ alkyl Gemini phosphate surfactant were tested, such as cmc value,wettability,emulsifier,antistatic property,antistatic property and so on. Compared with traditional C₁₈ alkyl phosphate surfactant, C₁₈ alkyl Gemini phosphate surfactant has lower cmc value, and better wettability,emulsifier,antistatic property,antistatic property. Then, compared with C₈ alkyl Gemini phosphate surfactant,C₁₀ alkyl Gemini phosphate surfactant and C₁₂ alkyl Gemini phosphate surfactant. The result indicate C₁₈ alkyl Gemini phosphate surfactant has better stability of foam, lower property of frothing, and better property of friction.